Space Containment Method and Containment Structures Comprising the Application of Said Method

ABSTRACT

The invention relates to a space containment method including the following steps: applying a flexible envelope, which is made from a material that can shrink in an essentially uniform manner, around a support frame, the frame being an assembly of frame elements; and subjecting the envelope to the effects of a suitable physical phenomenon in order to generate the shrinkage thereof. Following contraction, the envelope tightly hugs the support frame, thereby stiffening the containment structure thus obtained.

The present invention concerns a containment method for spaces assigned to various activities. It is also concerned with containment structures resulting from the application of this method.

According to a more specifically interesting, but by no means limiting application, the invention aims to make available to industrial enterprises a method and system allowing the containment of construction sites for a limited time, on their sites of execution.

In many cases it is indispensable to be able to work in temporary work spaces and which may be of large dimensions. This is for example the case for buildings slated for renovation or asbestos removal, for certain industrial units, for the refurbishing or rebuilding of yachts and other large ships, etc.

The establishment of such construction sites must satisfy several constraints, such as:

-   -   increasingly stricter regulations with respect to the execution         of industrial construction sites;     -   demands for environmental protection;     -   more demanding specifications issued by the clients;     -   a range of inadequately performing solutions and means which are         poorly adapted to the afore-mentioned constraints.

The traditional methods and devices for temporary cover of spaces or volumes, of the tent or column type, consisting of a pliable material stretched over rigid supports, are suitable for certain activities such as: gatherings of people (meetings, shows, meals, . . . ), storage of goods, etc., for which it is possible to set aside appropriate sites with a generally two-dimensional configuration. They are however, most of the time inapplicable to the covering of industrial sites, the location of which is dictated by the location of structures (buildings, boats, . . . ) to be renovated or converted, and/or by the configuration of the latter.

At the present time, temporary containment covers over construction sites consist traditionally of an already rigid structure and a cover (tarpaulin, cladding panels, fabric, textile, plastic film, . . . ) that is attached to this rigid structure by means of various types of fasteners or connecting devices, or that is simply placed as a cover over said support structure, then laterally tensioned and kept in such a situation of cover and tension by means of ground anchoring systems (for example as described in documents U.S. Pat. No. 2,044,351, or US-2003/01405569 [that are]practically inapplicable to the containment of construction sites). To ensure their ability to withstand to outside constraints, for instance resistance of the containment structures to inclement weather (wind and snow), such temporary structures impose a heavy load on the elements of the support structure and/or their anchoring system, in order to ensure the intrinsic mechanical strength.

The present invention aims in particular to provide an advantageous technical solution to the on-site cover problems of industrial construction sites of various kinds.

In more general terms, it proposes to facilitate the rapid, economical, and possibly portable construction of containment structures intended for diverse applications such as: temporary shelter, clean rooms, air locks for temporary work, temporary hangars, temporary storage, site huts, etc.

According to the invention, this objective is reached because of a method by which a subtle outer cover made of a material which is shrinkable in a generally homogeneous fashion, is wrapped around a support frame constituted by an assembly of framing elements and by subjecting this cover to the effects of an appropriate physical phenomenon resulting in its shrinkage, so that said cover, after its contraction, closely wraps around said framing elements, while achieving in this manner the stiffening of the obtained containment structure which now becomes a genuine construction.

According to a preferred working of the process, the support frame is made of tubular elements that are fitted together, preferably by connector pieces. In order to obtain a high-performance finished construction, these elements may be stressed during the assembly so as to add to the shrinkage of the cover material.

According to another example of implementation of the invention, at least certain elements of the support, frame or all of said elements consist of cables.

According to an interesting working of the process, the flexible cover is made of a material that is shrinkable after having been exposed to hot air and said cover is exposed to hot air after having been applied to the support frame, so as to then obtain its contraction on said support frame while it cools.

According to an interesting working of the process, the flexible cover is formed by a heat-shrinkable plastic film.

The containment structure according to the invention is especially noteworthy in that it comprises a support frame constituted by an assembly of framing elements and a flexible cover which becomes an integral part of said support frame by shrink-wrapping around said framing elements.

According to a preferred mode of execution the framing elements are assembled by simple interlocking, preferably by means of connector pieces, and they are maintained in an assembly position by the flexible cover thus providing for the stiffening of said framework.

It becomes clear that the invention allows in particular:

-   -   to erect light containment structures, with extensive mechanical         characteristics, that are easily and quickly put in place and         are portable, even in highly restrictive environments:     -   the protection, isolation and/or integration of construction         sites, works, objects and other [items], in their own         environment;     -   considerable control over the work areas;     -   to obtain excellent mechanical resistance to inclement weather.

The aforementioned objectives, characteristics and advantages, and more will become more obvious in the following description and in the enclosed drawings in which:

FIG. 1 is a perspective view, with partial sectional views, of an example of execution of a containment structure obtained through the working of the method of the invention.

FIG. 2 is a sectional view showing the placement of a portion of the flexible cover over a part of the support, frame, before subjecting it to a physical phenomenon causing it to shrink.

FIG. 3 is a section view analogous to FIG. 2 and shows the cover as it tightly wraps around the framing support after it has been subjected to the effects of the physical, phenomenon having caused its shrinkage.

Reference is made to said drawings to describe advantageous, although by no means limiting, examples of the workings of the method and of execution of the containment structures according to the invention.

According to this method a flexible cover 1, made of a material that, has the ability or particularity of shrinking in an essentially homogeneous fashion, is applied around at least a part of the support frame 2, consisting of an assembly of framing elements 2 a and this cover 1 is subjected to the effects of an appropriate physical phenomenon causing it to shrink, so that after the shrinking action said cover tightly stretches over said framing elements 2 a.

The framework 2 may be constituted of rigid tubular elements 2 a, of a length and diameter appropriate to the dimensions of the containment structures to be erected, and assembled by fitting them together. These tubular elements may be shaped so that they can be fitted directly into each other, or so they can be assembled by means of tubular connectors 2 b.

Depending on the dimensions of the containment structures to be created, the tubular elements 2 a. of the support frame 2 may be made of metal (steel, aluminum, . . . ), rigid polymers, composite materials.

It should be pointed out that another advantage of the method of the invention is that it is possible to fabricate the framing support from, elements of a relatively small section in relation to the dimensions of the containment structure. For example, according to another way of implementing the invention, certain framing elements or all of the framing elements of the framing support 2 may consist of metallic cables or fiber ropes. The framing support 2 may also consist of an assembly of rigid elements and cables.

More precisely, the section of the framing elements is adapted to the characteristics induced by:

-   -   the weight of the containment structure itself;     -   the shrinking capacity of the cover;     -   the environment of the construction (exposure to inclement         weather: wind, snow etc.);     -   use of the construction (storage of merchandise, containment of         work areas, etc.);     -   mechanical characteristics of the framing elements.

The cover 1 may be made of any flexible material featuring the particularity of shrinking in an essentially homogeneous fashion when it is subjected to the effects of an appropriate physical phenomenon that causes this reaction.

Advantageously the cover 1 may be created from a material that has the particularity or property to shrink while cooling after having been put into contact with hot air.

However it is also contemplated to obtain the shrinkage of the cover by subjecting it to the effects of other physical phenomena such as putting it into contact with cold air, exposure to electromagnetic radiation, etc., depending on the physico-chemical characteristics of said cover.

Preferably though, the cover 1 may consist of plastic, thermoplastic shrink wrap film such as a film of extruded polyethylene or other, featuring the particularity of shrinking on itself while cooling, after having been exposed to contact with hot air.

By way of a non-limiting example, the cover 1 may consist of one or several layers of thermoplastic film and represent a minimum cumulated thickness of 250 μm and a minimum contraction capacity of 1.0 Mpa. The average linear weight of a containment structure that is 6 m wide, 4.5 m high and with a dual slope of roof, with such a cover and framing elements of 30 mm diameter composite tubing, will be around 10 kg for the framing support and 5 kg for the cover.

The flexible cover may consist of a number of widths or of panels connected to each other by thermo-welding or otherwise. It may be transparent, translucent, opaque or tinted in any color.

After a simple fitting together of the framing elements 2 a, 2 b, the flexible cover 1 is applied at least around a part or around all of the framing support 2, depending on the dimensions of the containment structure to be fabricated.

The flexible cover 1 is then put into contact with hot air supplied by a generator of hot air 3 which is known as such, for example consisting of a mobile hot air generator installed within the enclosure formed by the framing support 2, covered by said cover and capable of adequately heating the volume of the construction (FIG. 2). It is also possible to use a hand tool with a directional jet (heat gun) to project hot air onto the surface of the thermoplastic film enclosing the framing support in order to then obtain by the cooling process the shrinkage of said film on the latter.

Shutting off the hot air supply results in the cooling of the flexible cover 1 which shrinks on itself, tightly wrapping the framing elements 2 a, 2 b which have been assembled by simple fit which has the effect of prohibiting the relative movements of these elements and allows to put the constrained framing support 2 under pressure and/or stress and consequently to stiffen all the elements and joints bearing the applied constraints. The containment structure created in this way presents a rigidity or stiffness and tightness that confer upon it in particular excellent weather-resistant qualities, even though its framing has been fabricated from elements of light weight and reduced section or diameter.

Shrinkage of the flexible cover over the support construction 2 may be performed progressively, by proceeding from one zone to the next, or simultaneously over the entire surface of said cover, depending on the dimensions of the containment structures.

The containment structures according to the invention may have different shapes: in the shape of a tunnel, with a single or dual slope roof, in the form of an arch, prism, parallelepiped, cylinder, etc. They may be guyed to the ground. They may or may not have other bearings over the span.

The relatively long elements of the structures (bays) may be pre-stressed to counteract the environmental stresses of the structure, for example dynamic wind pressure. 

1. Space containment method comprising the steps of: wrapping a flexible cover, being comprised of a shrinkable material, the material shrinking in a generally homogeneous manner, around a framing support, said framing support being comprised of an assembly of framing elements; and subjecting said flexible cover to effects of an appropriate physical phenomenon resulting in shrinkage, after contraction said flexible cover tightly enveloping said framing elements.
 2. Method according to claim 1, said framing support being comprised of tubular elements, said tubular elements being assembled together.
 3. Method according to claim 2, said tubular elements being assembly by connector pieces.
 4. Method according to claim 1, said framing elements being comprised of cables.
 5. Method according to claim 1, wherein said appropriate physical phenomenon is contact with hot air, said step of subjecting said flexible cover to contact with hot air being after said step of wrapping, said contraction by cooling and shutting off said hot air.
 6. Method according to claim 1, wherein said flexible cover is comprised of a thermoplastic film.
 7. Method according to claim 6, wherein said flexible cover is comprised of one or several layers of thermoplastic film featuring a minimal cumulate thickness of 250 μm and a minimum contraction capacity of 1.0 Mpa.
 8. Space containment structure, resulting from the method in accordance with claim
 1. 9. Space containment structure, comprising: a framing support being comprised of an assembly of framing elements and a flexible cover, said flexible cover being an integral part of said framing support by contraction around said framing elements.
 10. Space containment structure according to claim 9, wherein said framing support is comprised of tubular elements fitted together and maintained in an assembled position by said flexible cover tightly stretched over said tubular elements.
 11. Space containment structure, according to claim 9, said framing elements are cables, said flexible cover being attached by contraction around said framing support formed by said cables. 